DiSCIS Clinical Core Abstract The overarching goal of the Clinical Core is to engage, enroll, and retain participants in the Discharge Syndromes: Concordance and Interactions Study (DiSCIS) application. The investigators recognize the central role that human subjects play in this application and also the sensitivity of the information collected from study participants. All researchers will adhere to the highest level of ethical behavior in order to protect the physical and emotional wellbeing of the participants. The Clinical Core will support all projects outlined in the proposal through recruitment and performance of all clinic visits, including screening, initial, and subsequent study visits. Recruitment and all clinic events will be centralized at the Jefferson County Department of Health (JCDH) STD Clinic. In 2012, 16,119 patients (males=7,360 and females=8,759) received sexual health care at the JCDH STD Clinic. High prevalence of discharge syndromes including nongonococcal urethritis (about 25% of men), bacterial vaginosis (about 50% of women), and Chlamydia trachomatis (about 12% overall) are diagnosed and treated in this clinic. The JCDH STD Clinic and the University of Alabama (UAB) STD Program have an enduring partnership in STI research and STI-related patient care and a strong infrastructure already exists in this clinic for STI-related research. To maximize the success of the Clinical Core, we have assembled a clinical team with experience in designing, performing and completing longitudinal STI studies including couples studies. The specific aims for the Clinical Core are: (1) To centralize recruitment of men and women in regular sexual partnerships to create a cohort of participants to support all proposed projects, (2) To retain men and women in regular sexual partnerships for the duration of the study period, and (3) To collect accurate and complete participant information and biologics while protecting participant confidentiality. By supporting Projects 1-3, the Clinical Core will help to create new knowledge, advance diagnostic tools, and optimize therapy related to the most common discharge syndromes. The Clinical Core and its tight linkage to the Laboratory Core will ensure collection of quality specimens, efficiency and cost savings. The collective expertise of the Clinical Core team in clinical research study design, participant recruitment, and participant retention in prospective STI research including sexual dyad studies will provide a strong foundation for the success of all DiSCIS Projects while adhering to the highest standards of clinical research.